This invention (structure and method) relates to column and beam frame structure, and in particular to a novel structural interconnect organization (and related methodology) involving the quick setting, into full-moment-capability, of correctly design-positioned columns and beams. A preferred form of the invention, both structurally and methodologically, is described herein principally with reference to a unique, bearing-face collar-interconnect structure which joins adjacent columns and beams at nodes of intersection between them in a manner whereby, when a column and a beam are brought, through gravity lowering of a beam into place, into correct, design-intended, relative positions, they become instantly gravity-set substantially against further relative motion, and instantly stabilized in correct, full-moment and positional relationship with respect to one another.
To this end, the invention proposes a column-beam quick-set interconnect structural system and methodology wherein the ends of beams are joined to columns at nodes of intersection, preferably through unique collar structures that effectively circumsurround the sides and the long axes of columns, to deliver, through confronting bearing faces, compressive loads which are derived from moment loads experienced by the beams. These collar structures are configured in such a manner that, as the end of a prepared beam approaches its correct, design-intended position relative to a column, the collar structures both (a) guide these two components toward that correct relative disposition, and (b) instantly gravity-set and stabilize these components exactly as they arrive at that position. Not only does this very special action occur in accordance with the invention, so also occurs the then instant gravity-set-and-stabilized establishment of a full-moment interconnection between the subject column and beam. I refer to this significant characteristic of the present invention as a “drop-and-set” style of immediate, full-moment, properly-positioned connection.
For the purpose of illustration herein, the invention is described in the setting of a structural building frame, but it should be understood that various other kinds of structural frames may well also utilize the invention.
As will be seen, the invention is intended for use in conjunction with upright tubular columns each of a character having plural sides preferably distributed equiangularly around, and in common spaced relations relative to, the associated column's long axis. The interconnect structure of the invention uniquely is designed for fully compatible use between a beam and a column on any and every side of such a column. No matter which column side is involved, essentially exactly the same-character, full-moment, column-beam, properly-relatively-positioned interconnection develops. In other words, the invention is designed so that every full-moment connection created by it on each and every side of a column is always functionally the same. This feature of the invention can be visualized, therefore, as offering a kind of “omni-directional” functional symmetry relative to the long axis of a column. This symmetry concept will be more fully explained herein as the description of a preferred form of the invention unfolds below.
One other point should be mentioned here before advancing to a filler discussion of the preferred collar-form of column-beam interconnection. It is this. Immediate same-invention predecessor structures of mine did not necessarily invoke the collar-form connection approach. They did, however, embody the drop-and-set principle of interconnection mentioned above, as well as the principle just referred to above as omni-directional functional symmetry. Drawing FIGS. 11-13, inclusive, herein illustrate interconnect components in three different ones of these predecessor versions of the invention.
Returning now to the discussion involving the preferred collar-form interconnection, the delivery through compression of moment loads carried from beams to columns involves the development in the columns of vertically offset reverse-direction compression loads which create related moments in the columns. With respect to each and every lateral load that is experienced by a building frame constructed in accordance with the invention, all lateral loads are essentially equally shared by all of the columns, and a consequence of this is that, in comparison to building frame structures built conventionally, a building frame structure constructed in accordance with this invention prevents any single column from carrying any more load than is carried by any other column. As will become apparent, this important feature of the invention, as it performs, enables a building to be constructed in such a way as to exceed minimum building code requirements in many instances, and thus open the opportunity for using a building frame in accordance with this invention in settings where conventional frame structure would not meet code requirements.
The nodal connections which result from practice of the preferred form of the present invention function to create what is referred to as three-dimensional, multi-axial, moment-coupling, load transfer interconnections and interactions between beams and columns.
Focusing on the specific load-delivery interaction which occurs between a given single column and a connected single beam that bears a moment load, this load is coupled compressively into the column by the associated, single, nodal collar structure at plural bearing-face regions which are angularly spaced about the column's long axis. Compressive load-transfer coupling is not constrained to just one plane of action, or to just one localized region of load delivery. Compression couplets are created to take fuller advantage of columns' load-handling capabilities.
The illustrative and preferably proposed nodal collar structures include inner components which are anchored, as by welding, to the outside surfaces of columns, and an outer collar which is made up of components that are suitably anchored, also as by welding, to the opposite ends of beams. The inner and outer collar components are preferably and desirably formed by precision casting and/or machining, and are also preferably pre-joined to columns and beams in an automated, factory-type setting, rather than out on the construction job site. Accordingly, the invented collar components lend themselves to economical, high-precision manufacture and assembly with columns and beams, which can then be delivered to a job site ready for accurate assembly.
As will become apparent from an understanding of the respective geometries proposed by the present invention for the collar components, these components play a significant role during early building-frame assembly, as well as later in the ultimate performance of a building.
At the regions of connection between beams and columns, and with respect to pairs of adjacent columns standing upright approximately correctly (vertically) in space on a job site, as beams are lowered into horizontal positions, the outer collar components that they carry at their opposite ends seat under the influence of gravity through special, angular, bearing-face geometry provided in them and in the confronting inner column components. This bearing-face geometry effectively guides and collects a lowered beam, and the associated two columns, into stabilized, gravity-locked conditions, with these now-associated beam and column elements then essentially correctly aligned and positioned in space relative to one another. Male/female cleat/socket configurations formed in and adjacent the confronting bearing-face portions of the inner and outer collar components function under the influence of gravity, during such preliminary building construction, not only to enable such gravity locking and positioning of the associated frame components, but also to establish immediate, full-moment stability, even without further assembly taking place at the nodal locations of column-beam intersections.
Following preliminary frame assembly, appropriate tension bolts are preferably introduced into the collar structures, and specifically into the components of the outer collar structures, effectively to lock the inner and outer collar structures in place against separation, and to introduce available tension load-bearing constituents into the outer collar structures. Such tension load bearing plays an important role in the way that the structure of the present invention gathers and couples beam moment loads multidirectionally into columns.
Confronting faces between the inner and outer collar components function as bearing faces to deliver, or transfer, moment loads (carried in beams) directly as compression loads into the columns. In particular, these bearing faces deliver such compression loads to the columns at plural locations which are angularly displaced about the long axes of the columns (because of the axial encircling natures of the collars). Such load distribution takes substantially full advantage of the load-carrying capabilities of the columns with respect to reacting to beam moment loads.
Accordingly, a building frame structure assembled in accordance with this invention results in a quickly assembleable, and remarkably stable and capable frame, wherein all lateral loads transfer via compression multiaxially, and at distributed nodes, into the columns, and are born in a substantially relatively evenly and uniformly distributed fashion throughout the entire frame structure. Such a frame structure requires no bracing or shear walls, and readily accommodates the later incorporation (into an emerging building) of both outer surface skin structure, and internal floor structure.
The nodal interconnections which exist between beams and columns according to this invention at least from one set of points of view, can be visualized as discontinuous floating connections—discontinuous in the sense that there is no uninterrupted (homogenous) metal or other material path which flows structurally from beams to columns and floating in the sense that beams and columns could, if so desired, be nondestructively disconnected for any particular purpose. Thinking about the latter consideration from yet another point of view, the connective interface that exists between a beam and a column according to this invention includes a portion which experiences no deformation during load handling, such portion being resident at the discontinuity which exists between beams and columns at the nodal interfaces.
These, and various other, features and advantages which are offered by this invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawings.